Relay type key sender



Aug. 7, 1945. w. T. POWELL RELAY TYPE KEY SENDER Filed Oct. 16, 1943' 5 Sheets-Sheet l I INVENTOR. wmFRED T. POWELL.

MARKER Aug. 7, 1945. w. T.- POWELL RELAY TYPE KEY SENDER Filed OQ t. '16; 1943 5 Sheets-Sheet 2 INVENTOR. W\NFRED T. fOWELL BY A llll'llllll lll Al'z lg.;7, 1945. w. T. PowE LL.

' RELAY TYPE KEY SENDER Filed Oct. 16, 194.5 s-sheets-sneet 3 INVENTOR. wmFRED T. Po'wELL 8 5. w. T. POWELL 2,331,515

RELAY TYPE KEY SENDERY Y Filed Oct. 16, 1943 55heets-Sheet 4 ain BF"? 1 1 -GNVENT0R. human T. POWELL.

Aug. 7,1945. w. T. POWELL RELAY I'YPE KEY SENDER 5 Sheets-Sheet 5 Fil ed Oct. 16, 1943 D\SCHARGE INVENTORQ WINFRED T. POWELL Fig.5

inventiontherelis provided a a sender {and a relatedcounting'relay chain which :ooperate to control the transmission of relayifielay l u isenergized:

soon as this sleeve rel y is operated, it closes a "circuit f or operating the negative pole of battery, 'baclr'contact and armature of the cut-off ;relay Patented Aug. 7; 1945 I This invention relates to automatic telephone In accordance with'the main feature of the generated impulses for selective operation of switching devices.)

Another 'featureof the invention relates to a novel relay'jarrangement for generating properly "systems'and more particularly to impulse send- I 'ing-arranjgements for use therein. j

key-operated register timed impulses usefuljin the operation of automatic" telephone systems.

Other features of the 'inventionwill appear from the detailed description" and: claims when ak w h draw n when arranged in the order named and with Figs; 3 andf' i grespe'ctively placedbelow Figs. I

1 'and '2 diagrammatically represent" an automatic telephone system including an operators position"togetherfwith a key-operated register sender and impulselgenerating means, all cooperating to control selector and connector switches indicated byrectangles; and'Fig'. 5 is a simplified diagram showing the circuits. for operating the impulse-generatingrelay. A v

the invention will 'hest be It isbelieved that understood 'by' describing the operation, involved in'establishing a'telephone connection fromsube station A'jto substation B In initiating a call,

t the subscriber at A removes telephone handset from its cradle to closethe related telephone line. There'upon switching frneans (not shown) co'nnectsfthis line to the cord circuit which terminates in plug P.

. J of a trunk leading to themachine switching office, the sleeve in an obvious circuit. As

line relayll from the winding of this relay,

l2, hack contact" and vaiun'atmre of' relay l 3,' .iront contact and armatureof the sleeve relay ID to the positive pole of the line'relay ll completes a circuit forvoperof battery. The energization atin'g in; series, one of the tens lock-out relays which cooperate to insure j when the operator inserts the calling plug P of the cord: circuit a into the jack ES PA E T 0 FF! E .v V "2 ,3s1,516 it if; If, I t v l REnAY'TYPE KEY sENnEa' 3 Winfred moan,- Roche 1 Stromberg-Carlson Company,

' a a: a corporation of New Xork Application October 16 in which; Figs. land 2 I tinuity spring and negative pole of' a battery, winding of this rela'yy' up'pe'rm lock-out circuit canhe traced from the positive pole iii-battery, continuity spring and back contact ofthe tens lock-out relay [4 throughthe continuity springs and packcontacts of the relays hill, W

star, .N- -La si l icrut f I relay 2! energized, the rela' and armature 290i relay of'battery. "The relay 26 which iS Qff'th winding of this relay;

use but also close acircuitfor operating th is completed from the posit l5 and I6, conductor I 1 inner "back contact and continuity spring of relay ll'4 ,-win'ding of this relay, conductor l8, front contact and armature of relay ll; conductor 20, winding of the units {lockout relay 2|, its inner continuity-spring and'fback.

back contacts and contact, conductor 22,"ou'ter continuity. springs of lockout relays 23; 2 4"-and relay l4 'andthe units relay 2| are'energized this circuit "and complete a: locking"circuit;jas follows; independently of the remaining fre lays of the marker. At the tens-relay I' l," thedocking ing circuit is completed through the} inner? conbattery'. It will be j'no d that while the relays Hand 2 [are thus locki': pe r ated, the remaining tens and "units relaysun the v marker are preventedffrom] operatingsinceitheir operating circuits are' interrr pted "at the "relays l4 and 21'. With'the tens relay l4"and"the' units a circuit from t operated in negative poleoi contact and armature of the relayf' 2 'l'; arm are 28 and front contact of relayf i4"; ,frontif 21'; to'the po siti the tens finder relay 31' andth e u nits finder 13513 traceablefrom the negative pole of bat T "conductor 35 lowermost armature and front contact of relay 30"; contact and armature'36 of units llockf-outir lay 2!, to the positive'po'le of battery. Finder relays 3| and -32, when thus opera ted notpnlyjextend the allotted sender "tothe cord circuit area cutoff relay l2 and the holding r 1ayf31gT 1 n; v 10f battery,

e pole J mature n fie ile n wl j an herma- -armature of this relayf'to I (provided. relay 4la polarized relay is. of. the

series of the. relay 31, to the negative pole of battery. Relay v the high resistance winding of 'elay 31, but. does operate after relay 31 operates and short circuits its high winding at armature and front contact.

When the cut-01f relay I2 operates, it opens the operating circuit of the line relay H which relay releases to open the operating circuit and thereby release the markerre-lays ['4 and- 2'l"'s,o thatthe marker is available for use in connection with succeeding calls.

Also, when the holding relay 31 is operated, it completes an energizing circuit for relay 21' of the al-lotter, this circuit extending from the negative pole of battery, lower winding, of this. relay, conductor 40,. left- (1 front contact. andarmar tureof relay 31, to the. positive pole of battery. Relay 21, on operating closes alocking circuit for itself from the negative pole. of battery,- its upper winding, front contact and lowermost armature of relay 26,.to the positive pole ofbattery.. The. relay 21 interrupts. the circuits. of the relays. 26 and 30. and extends the allotting circuit tothe relaysv 25a and 30a associated with a secand" finder (not shown)..

Furthermore, on the. operation; of. the holding relay 31 the relay, of the sender (Fig. 3) is energized ina circuit completed from the negative pole. of. battery, winding of this relay, conductor 43, armature and back contact of a similar. relay. 4la at. asecond sender of the group is not operated armature and backcontact of relay 12,. conductor 42, outer .f'ront contact and'armature of. relay 31,. conductor 43, contacts ofthe wipe-out key W. 0., to the positive poleofbattery. Relay 4I,.on. per1- ating, closes a locking, circuit for itself through its upper front. contact'and armature andthrough the contacts of the sender cut-off key .45 to. the

positive pole. of battery. Also, at thelower armature and front. contact of relay"4l,,, a. circuit is closed for lighting the signal lamp 46., as an indication. that sender #1. is. in use. Furthermore, relay 3T closes a locking circuit. for finder relays 31$ and 32,. atits left hand. inner front. contact. In addi'tion,. a. circuit. is completed by relay 4| for operating the polarize,d..relay 4.1 which. is provided with armatures 41a, 41b and 4.10. This construction wherein its 416 and 410 remaini-nthe. positions to which they are. moved .when.the relay operates. It. should be pointed out. that when either of the windingsv of. this. relay is energized in the direction of the. arrows these varmatures move to the left.

It. may be. well, at this point, to interrupt. the general'description of the. system to point. out. in detail how the polarized relay 4-1 swings its armatures 41a, 41b and'41c alternately to the right andto the left at a speed of about ten. complete cycles per'second to simulate the impulses com monlygenerated by a. dial sender, the operation of this relay proceeding continuously while it is transmitting a series of impulses corresponding to a given digit. For convenience in und'erstand-. ing the operation. of the. relay .41, the circuits thereof are shown in simplified form in Fig. '5.

Whentherelay' 41 operates, as above described,

armatures 41a,.

it closes an actuating circuit for the relay 41,

I2 does not operate in series with its own inner right hand traceable from the positive pole of battery, armature and front contact of relay 4|, conductors I I0 and Ill, through resistance R3, through the lower winding of relay 41, resistance coil Rl to the negative ole of battery, also through the resistance R2 in multiple to the negative pole of battery. Since only the lower Winding X of relay 41' is energized, the energization being in the direction "of the arrow, relay 4*1 quickly swings its armatures'to the left, as illustrated assuming the armatures to have been in their rig-ht hand: positions. For convenience in description this operation is designated I.

When somewhat later, the relay 12 is energized, it causes the relay 41 to quickly swing its armatures to the right. This action is effected in a ci-rcuit traceable from the positive pole of battery, armature and front contact of relay 12, armature 41c and front contact, conductor H2 to Junction. H3 where the circuit divides, one branch extending through the resistance Rl to the negative poleof batteryand. the other branch extending through the. winding X of relay 41, resistance R2 to the negative pole of battery. It

Will-be noted that the. current is therefore reversed in the lower winding X of relay 41 so that this relay swings its armatures. to the right. Also, when the relay 12 is operated, the condenser H4 and the winding Y of. relay 41 are. short-circuited at this time, by a circuit extending from the. positive pole of battery, armature and front contact of relay 12, armature. 41c and front contact,con.ductor H2, winding Y of relay 41, upper front contact and armature of. relay 12, condenser H4, front contact. and armature of relay 12, conductor H5 to the positive pole of battery. Since the direction'otthecurrent, in the winding X. f relay 41 is now reversed and since the currentin winding Y is short c'ircuited, relay 4'1 operatesits armatures to the right. This operationis conveniently referredto as II.

When the relay 41 moves its armatures to the right, the positive potential at the junction point I I3 is removed. Then, acircuit iscompleted from the positive pole of battery. conductor I I5, armature and front contact of relay '12, condenser l I 4,'upper armature and front contact of relay 12, winding .Y of relay 41' to the negative pole of battery, either, through the. resistor RI or through the winding 'X of relay 41 and the resistor R2. This circuit causes the condenser H4 to start charging. While. this condenser is charging, the currentflowing throughthe. Y winding of relay 41 opposes any tendency of this relay to operate its armatures to the left even though the current in winding Xtends to reverse, as in the case of operation I, above, When the charging current through thewinding Ygof relay 41 drops below a certain value'as the condenser I I4 becomes charged, the current flowing in the winding X of relay 41 will. become effective to cause the relay 41 to operate it armatures to the left. This may be called operation III.

, When the polarized relay 41 has moved its. ar-

matures to the left,. positive potential is;replaced at the junction H3 -store digits corresponding ,In the case of 'fer relays 51, 53 and the relay 69, conductors paratively slow operations.

The allotted sender, that is the one herein illustrated-is now in condition to the called subthen send out im- This sender, as

scribers line designation and pulses in accordance therewith. well as other senders in the group, controlled by a single strip of ten digits keys which can be selectively associated with a sender taken for use. Each sender includes'a relay register for each digit of the subscribers designation so that a thousands, a hundreds, a tens and aunits register are herein provided. Each register comprises four relays, marked A, B, C and D. It will be appreciated that by selectively operating the four mentioned relays of any register, ten-different. combinations thereof may be established to enablethis register to store any one of ten digits. The combinations of these relays, necessary to record any one of ten digits, is shown opposite the corresponding key of the mentioned strip of ten sender keys. Where the finder relays 3| and 32 were operated (as previously explained) to connect the sender to the cord, a closed circuit including back contact I20. of relay 15 is placed across the line leading to the automatic switchboard-by way of the plug and jackBand'J. g

Let it be assumed that the wanted number is #2630," thecperator will first depress the #2 sender key. This completes a circuit from the positive pole of battery, conductor 54, contacts of the-#2 key, conductor 65, armature and front contact of the sender relay-4l and conductor-6 6,

armatures and back contacts of the transfer relays51, 58, 59 and 60 of the units-, tens, huni dreds and thousands registersrespectively, winding of the register relay lBfto the negative pole of battery. Relay 13, on operating, completes a locking circuit for itself (after the key is released) from the'inegative pole of battery, its

winding, as well as its, inner front contact and armature,winding of the transfer relay 60, conductor Bl, lower back contact and armature of relay 62, conductors 63 and 43 to the positive pole of battery at the wipe-out key W. 0. Relay 50 operates in the locking circuit .of relay 1B,

' The operator continues to operate selectively the sender keys to store up the remainder of the subscribers designation in the hundreds register; the tensregister and in the units register.

the hundreds. digit #6, the operator presses the #6 key to close a circuit'from the Operations I and is selectively 4 to be operated to 1 positive pole of battery, conductor 54 contacts" of this key, thence ov'er conductor 55, front contact and armature of the senderirelay 4 I, conductor 56, armatures and back contacts of the trans- 59, armature, and front contact of the thousands tranfer relay50, conductor 61, winding of the' hundreds register relay 2A, to the negative pole of battery. Relay LA, on operating, the key is released) through its winding, its front contact and armature, winding of the hundreds transfer relay 59, back contact and armature of B3 and 43, and thence to the positive pole of. battery at the wipe-out key' W50.

In addition, when the operator depresses the #6 key, a circuit is closed for the hundreds reg- I ister relay 20 from the positive pole of battery,

closes a locking circuit for itself (after conductor '54, contacts of key #6, conductor 68, front contact'and armature of relay 4|, conductor 10, armatures and back contacts of relays 51, 58, and 59, armature and front contact of relay 60, winding of relay 2G to the negative pole of battery. Relay 26, when operated, locks itself (after the key is released) in this condition in multiple with relay 2A. Relay 59 operates in series with this locking circuit.

Similarly, when the operator presses the #3 key of the sender corresponding to the #3 tens digit, the relay 3C ofthe tens register will be operated and will lock itself operated (after the key is released) in series with the tens transfer relay 58, in a circuit including the conductors 63 and 43, extending at the wipe-out key W. 0.

Next, the operator'depresses the #0 key of the sender to register the units digit #0 by operating the relays 4C and 4D of the units register. Relays 4C and 4D, on operation, close their looking circuits (after the key is released), as well as an operating circuit for the units transfer relay 51 similar to that, described in the case of the other registers.

As soon as the operator has caused the thousands relay to store the thousands digit with the consequent operation ofthe thousands transfer relay and whilethe operator is continuing to set up the hundreds, tens and units digits on the corresponding registers, other operations take register is operated, it'closes an energizing circuit for the relay 12 (Fig. 4) from the negative pole of battery, winding of this relay, conductor 13, front contact and armature of relay 00 to the positive pole of battery- Relay 12' on operation closes a' locking circuit for itself through its front contact and armature, conductor 42, front contact and armature of relay 31 and thence over conductor 43, wipe-out key W. O. to the positive pole of battery. It will be recalled that thepolarized relay 41 moved its armatures to the left as soon as the relay 4| operated on the seizure of the #1 sender. However, on the energization of relay12, the polarized relay moves its armatures to the right constituting the #II operation previously described. Relay 12 also closes an operating circuit for the impulseresponsive relay 14 from the negative pole of battery,windingof this relay, back contact and armature of relay 15, front contact and armature of relay 12, armature and back'contactof relay 16 to the positive pole of battery. The operation of the impulse responsive relay 14 closes an obviouscircuit for the slow releasing relay 11-. The operation of this relay in turn effects the, operation of the relay ,CX from the negative pole of battery, winding of this relay, upper back contacts and armatures of counting relays CI to Cl! inclusive, conductor 19, front contact and armature of relay 11, back ,contact and armature of the relay 80, to the positive pole of battery. The polarized relay 41 (impulse generating) now continues to repeat its operations III and IV, described above, to swing its armatures alternately to the left and to the right at a speed of about ten complete cycles per second to simulate the, impulses commonly generated by a dial sender. When the polarized relay 41 now swings its armature to the left in accordance with the first #III operation, the slow operate relay 8| is energized from the negative pole of battery winding of this relay, back conto the positive pole of battery tact and armature of the relay 15, back contact and armature of the change-over relay 1'6, armature 473, front contact and armature of relay 72', to the positive pole of battery. It should be mentioned that While the relay 8| is slow-operating, it should be fast enough to operate withinthe time of a pulse generated. by the polarized relay 4']. It should be noted that while the armature flb is in its left-hand position, it shortcircuits the relay [5. When, however, the polari'zed relay moves its armatures to the right, the relay 1'5 is'energized in series with the relay 8|, this circuit extending from the negative pole of battery, winding of the relay 8|, its front contact and armature, winding of the relay 15, front contact and armature of relay [2, armature and back contact of relay (6, to the positive pole of battery. Also, when the relay operates, it interrupts at its armature I and back contact, the trunk line circuit including the conductors Bland 85, so that the making and breaking of this circuit to transmit code impulses corresponding to digits of the wanted number is now controlled by the armature 41a of polarized relay 41. As soon as the relay 15 operates, it opens the energizing circuit of the impulse responsive relay 14 which. deenergizes. When the impulse responsive relay 14 releases, it closes a circuit for operating the Cl counting relay from the negative pole of battery, winding of this re lay, lowermost front contact and armature of the relay CX, front contact and armature of the relay (1, which is too slow to release on the temporary interruptions of its operating circuit by the release of the impulse relay, and thence to the positive pol of battery at the upper back contact and armature of the impulse responsive relay MI Now, when the polarized relay 4'! moves its armatures to the left again, the impulse responsive relay 14 is again energized from the negative pole of battery, winding of this relay, conductor 83, front contact and armature of relay 15,, back contact and armature of change-over relay 16, back contact and armature 411), front contact and armature of relay 12, to the positive pole of battery. Also, when the polarized relay 4! moves its armatures to the left, it opens the impulse circuit including conductors 84 and 85 respectively connected to the tip and ring conductors of the cord circuit now in use. tinuity of the impulse circuit, including the conductors 84 and 85, is controlled at one of the contacts of the wipe-out key W. O. The mentioned opening of this impulse circuit constitutes the first thousands digit impulse transmitted through the cord circuit and the trunk to the automatic switches. In response to the lastmentioned operation of the impulse responsive relay 14, the relay CX releases but the counting relay Cl is now locked operated from the negative .pole of battery, Winding of this relay, its inner, upper front contact and armature through the back contacts and armatures of the counting relays, namely, C2 to CH inclusive, con- It should b pointed out that the conwinding of this relay, lowermost front contact and armature of relay Cl, back contact and armature of relay CX, front con-tact and armature of relay 11, back contact and armature of the impulse responsive relay 7'4, to the positive pole of battery. When the polarized relay 41 now moves to the left, it interrupts th mentioned impulse circuit including the conductors 84 and 85 to start the second impulse over the trunk. Also, under this condition, the impulse responsive relay I4 is energized in a circuit previously described. When the impulse responsive relay M is thus operated, it opens the circuit which has been holding the counting relay Ci operated so that this last-named relay releases. Now, when the polarized relay 74 moves its armatures to the right, itinterrupts the operating circuit of the impulse responsive relay i l, and closes the impulse circuit including the conductors 84 and 85 to end the #2 impulse. When the impulse responsive relay 74 releases, it closes an energizing circuit for the counting relay C3 from the negative pole of battery, winding of this relay, front contact and armature of the relay Ch ba-ck contacts and armatures of relay CI and CK, front contact and armature of relay 11, back contact and armature of the impulse responsive relay M to the positive pole of battery. Since that portion of the counting relay chain corresponding to the transmission of two impulseshas been actuated, change-over relay is is now operated in a circuit traceable from the negative pole of battery, winding of this relay, armature and back contact of the relay 8!], conductor 81, armature and front contact of the thousands register transfer relay 6D, armature and back contact of relay IA, armature and front contact'of relay IB, armatures and back contacts of relays IC and ID, conductor 88, front contact and armature of counting relay C3 and thence through the back contacts and armatures of the remaining counting relays C4 to ductor 19, front contact and armature of relay Tl, back contact and armature of relay 80 to the positive pol of battery. When the polarized relay 41 next swings its armatures to the right thereby ending the first trunk impulse, the operating circuit of'the impulse responsive relay 14 will be interrupted again at the armature 41b and the trunk circuit will be closed at armature 41a. Counting relay C2 will now be operated from the negative pole of battery,

CH inclusive, to the positive pole of battery. Relay 16, on operating, completes a locking circuit for'itself from the negative pole of battery, winding of this relay, back contact and armature of relay 89, front contact and armature of relay 15, front contact and armature of relay 12, and thence through conductors 42 and 43 to the positive pole battery at the wipe-out key W. 0. When the change-over relay 16 operates, it interrupts the circuit which has been holding the relays 15 and 81 operated, thereby causing these relays to release. Sincethe impulse responsive relay 14' is released for a relatively long period, the slowreleasing-relay 11 will now release to cause the release of the counting relays C2 and C3. When these last'two relays release, the relay will be energized in a circuit traceable from the negative pole of battery, winding of this relay, front contact and .armature of the change-over relay 16, through the back contacts and armatures of the relays OK to Cll inclusive to the positive pole of battery.

When the relay 80 energizes, it effects the operation of the relay 62 in a circuit extending from the negative pole of battery, winding of this relay, back contact and armature of relay fill, conductor 9|, front contact and armature of relay 8! front contact and armature of relay 12, to the positive pole of battery. Relay 62 on operation prepares a locking circuit for itself in series with the relay 90, but which is not yet effective because relay has both terminals of its winding connected to positive battery. On

'. register relay IB "and tact and armature of relay wipe-out key W. 0.

' counting relay chain to interpose the vC2 to operate. polarized relay 1 ized relay now operates to the operation of relay C3."

battery, back contact release of relays C2 and C3. The release of the the operation of the relay 62, th thousands the thousands register transfer relay 60 release but only if the hundreds register transfer relay 59 has been operatedas a result of the completion of the registration of the hundreds digit by the operator.

It will be understood that if the relay 59 of the hundreds register-has not been operated, then a substitute holding circuit for the thousands register transfer relay 60 and the thousands register relay is completed through back con- 59, conductors 63 and 43, to the positive pole of battery, at the Following the transmission of the impulses corresponding to the thousands digit, it is necessary to introduce a delay before the hundreds series of impulses is transmitted. This is essential in'order to'afiord timefor the switching means in the automatic equipment to complete the trunk hunting operation in the group corresponding to the thousands digit. This delay is interposed by again operating a portion of the chain of counting relays, the interval being,

terminated by the operation of the counting relay C3. It should be mentioned that this second operation of the counting relay G3 has no relation to the prior operation of this same relay in the course of sending the thousands digit which was assumed to be #2. It should be pointed out'that during this operation of the mentioned delay, the actuation of the armature 41a of the polarized relay 4! willlnot transmit impulses over the signalling circuit to the distant'oflice, since at this time the signalling circuit is maintained uninterrupted at the back contact and armature 120 of the relay 15.

' On the next operation of the armatures of the polarized relay 41 to the left, following the operation of the relay 80, theimpulse' responsive relay 14 will be operated and it will in turn effeet the operation of the slow releasing relay 11. Also, the relay CX of the counting relay chain will beoperated. .When thepolarized relay 41 operates to the right, the impulse responsive relay 14 will deenergize and the counting relay CI polarized relay will operate. Now, when the moves to the left, the impulse responsive relay 14 will operate again which in turn causes the relay CX torelease. Thepolarized relay next operates to the right which causes the impulse responsive relay 14 to release and cause the counting relay On the nextoperation of the to the left, impulse responsive relay 14 operates and CI releases. The polarright to effect the release 'of impulse responsive relay I4 and the Since the counting relay relay 80 are operated at this well as the locking 16 are inter- The change- C3 and also the time, the operating circuit as circuit for the change-over relay rupted so that this relay releases.

. over relay, on releasing, i nterrupts at its uppermost armature and front'contact, the operating circuit of the slow releas1ng relay 80' which shortly thereafter releases.

The release of relay 15 closes a circuit from the positive pole of of relay I6, inner upper front contact of relay 12, inner upper back contact of "relay I and windingof relay 14 to the negative pole of battery for operating relay 1'4. During the interval between the releaseof relay 16' and the'relea'se of relay 89, positive battery is removed from conductor 19 which effects the relay 80 again closes the previously described energizing circuit for the relay CX. With the armature 41b of the polarized relay in its left hand position, the slow-operate relay BI is operated from the negative pole of battery, winding of this relay, back contact and armature of relay-15, back contact and armature of relay l6, armature 41b, front contact and armature of relay 12, to positive pole of battery. If the hun-' dreds transfer relay 59 has been operated as a result of the completion of the registration of the hundreds digit, then when polarized relay 4''! is operated to the right for removing positive pole of battery from the junction of the relays BI and 15, the relay 15 will operate from the negative pole of battery, winding of the relay 8|, its lower front contact and armature, winding I of relay I5, front contact and armature of relay tive'pole of battery,

of relay 62, winding of relay 90, conductor 92 tioned short circuit for the relay 12, back contact and armature of the change over relay 16, to the positive pole of battery. The operation of the relay 15 interrupts the energizing circuit of the impulse responsive relay 14 which releases andinturn causes the operation of the relay Cl, as previously described. 'The release of relay 8!) disconnects positive battery from conductor 9| which permits relay 90 to operate in series with the locking circuit of relay 62. This circuit may be traced from the negawinding and front contact and'upper front contact of relay 12 to the positive pole of battery.

In'the event that theregistration of the hundreds digit has not been completed at this time, then the hundreds transfer relay 59 will not be operated with the result that there will be a short circuit around the relay T5 to preventthe operation of this relay and consequently the sending out of the impulses corresponding to the hundreds digit until this digit has been re.- corded on the hundreds register.

15 is traceable. from the positive pole of battery at theiwipeout key W. 0., conductor 43, armature 94 and front contact of the sender relay M, conductor 95, uppermost armature and back contacts of the units transfer relay 51, the tens transfer relay 58 and of the hundreds transfer relay 59 (which is assumed not to be operated), front contact and armature of relay 89, front contact andarmature of relay 90, conductor 96, upper front contact and armatureof the relay 8! and also the lower front contact and armature of this relay to one terminal of the winding of relay 15, the other terminal of this winding being also connected to the positive pole of battery, through the front contact and armature of relay l2, and through the back contact and armature of relay 16.

When the polarized relay 4'! moves to the left, the impulse responsive relay 14' is again operated and causes the release of the relay CX,

, as previously described. The relay 4'! will con- The menrelay Cl operates, following #6 impulse, it connects ground potential to change-over relay 16, and thereby stops the sending of further hundreds digit impulses over the impulse circuit, including conductors 84 and 85, as Will'now be set forth. When the polarized relay 74 operates cuit being interrupted at armature 43b. When the impulse responsive relay l4 releases, it closes an energizing circuit for the counting relay C1, from the negative pole of battery, winding of relay 0?, front contact and armature of relay C5 and thence through the lowermost back contacts and armatures C5 to CX inclusive, front contact and armature of slow-releasing relay 17, back contact and armature of the impulse responsive relay M, to the positive pole of battery'. :Change-over relay 16 is now operated fromthe negative pole of battery, winding of I this relay, armature and back contact of relay g flmconductor .81, armature and back contact of relay iii armature and front contact of relay fill, armature and front contact of relay 2A, armature and back contact of relay 2B, armature and front contact of relay 2C, conductor Illduppermost front contact and armature of relay CI and thence through the back contacts and armatures of relays C8 tow-C III: inclusive, to the positive pole of battery. When the changeover relay operates, it interrupts the holding circuit of the relays 8i and 15 which release.

Since the impulse responsive relay M'has re leased for a relatively long interval, the slowreleasing relay I1 will also release. This, in turn, efiects the release of the counting relays Cl and C6. With the change-over relay 1B operated and with the counting relays C6 and C! released, slow-releasing relay fliiwill be operated from the negative pole of battery, Winding of this relay, front contact and armature of relay [6, uppermost back contacts and armatures of relays CXto- Cl l inclusive, tothe positive pole of bat- -tery.

When relay 80 operates, it efiects the energization of the relay 69 in a circuit that extends from the negative pole of battery, winding of this'relay, upper armature and back contact of relay Hi2, front contact and armature of relay Bil, conductor 9i, front contact and armature of relay 36, upper front contact and armature of relay 72, to positive pole of battery. With the relay 69 thus operated, it closes a locking circuit for itself in series with the relay )2 which later'results in the operation of the relay H32, after the measuring off of the intradigit impulses for providing the intra-digit pause. This circuit is completed from the negative pole of battery, winding of relay 69, its front contact and armature, winding of relay I62, conductor 92, front contact and armature of relay F2 to the positive pole of battery. Before the release of relay Bil, relay M32 is short circuited by the positive pole-of batteryon conductor 9|. The hundreds transfer relay 59 will have one of its operating circuits interruptedat the lowermost back contact and armature of relay 69. However, the relay 59 will release only if the tens transfer relay 58 has been operated as a result of the complete registration of the tens digit by the operator, since otherwise, relay 59 will be maintained operated over a circuit completed at an armature-and back contact of relay 58, conductors 5 3 and 43,. to the positive pole of battery atwipe-out key W. 0. Of course, when the tens transfer relay is energized,it interrupts the locking circuits for the operated hundreds register relays 2A and 20..

On the next operation of the polarized relay 41- to the left, after the operation of the relay 80, the impulse responsiverelay- M will be operated. The impulse responsive relay [4 causes the slow-releasing relay 1! to operate, which in turn causes, the relay CX of the chain to be operated. The chain of countingrelays will then beoperated in succession, to effect adelay between the hundreds digit and the tens digit, the interval beingterminated by the operation of the counting relay C3, as already described. Relay C3' causes the change-over relay l6 and the relay 80 to release again inv preparation for the transmission of the tens digit. If at this time the tens digit has been registered, the tens transfer relay 58 will then operate and the transmission of the tens digit impulses will take place over the impulse circuit including the conductors 84 and85,.in the manner previously described. In the course of transmitting these tens impulses,'the counting relay chain will operate ,until its relay C4 isenergized. With relay C4 operated, thechange-over relay #6 will be operated in a circuit extending from the negative pole of battery, windingof this relay, armature and back contact: of relay 80, conductor 8?, back contacts and armatures of the, thousands transfer relay 6! and of the hundreds transfer relay 59, armature and front contact of the tens transfer relay 58, armatures and back contacts of register relays 3A and 3B armature and front contact of relay 3C, armature and back contact of relay 3D, conductor I09, front contact and armature: of relay 04 through the back contacts and armatures of the relays C5 to Cll inclusive, to the positive poleof battery. The change-over relay will lo'ck itself operated as previously set forth. As 'aresult of the operation of this relay, impulse responsive relay M will fail to operate and, in turn, will effect the release'oi the slowreleasing relay l-l. Relay l1 effectsthe release of all the relaysofthe counting chain. Next, the relay 83 operates in the manner previously set forth." On the operation of relay 83, the relay H0 (Fig. 2)' will operate. in the same manner as relay 69, as described above.- .To effect a similar delay following the transmission of the tens digit impulses, the counting relay chain will operate its relays in succession, as previously described, until the relay C3 operates.- Thereupon, change-over relay T6 and the relay '86 will be released again in preparation for the transmission of. the units digit impulses, if the units transfer relay "5! has-been operated, otherwise the apparatus will waitiuntil relay 5? is operated.

-Meanwhile, after the operator has completed the registration of the units digit, she operates the sender cutoff key t5; This interrupts the locking circuit which has held the relay ii operated. The release of relaydi frees the key set from sendert l whichhas been in use. The release of relay 4|, at its lower armature and front contact, extinguishes the signal lamp 5% p to indicate to the operator that the key set has ingfor the. #1 sender to finish the impulsing in of relay Cl I to ground.

effects the release of the relays BI and 15, sender positive pole of battery at the wipe-out accordance with thedesignation stored in the #1. sender. 7

It will be assumed that the units digit is and that, impulsing is in progress on this last digit of the wanted line designation to the stage where the ninth impulse hasbeen completed.

When the. polarized relay 4'! operates to the left to start 'thete'nth impulse of the units digit, relay 14 is operated thereby and the relay 4? at its armature 41a. opens the impulse circuit to start the tenth impulse, counting relay C9 releases but countingrelay CID is now inits operated position When the polarized relay 41 operates 'to'the right, the impulsecircuit in cluding the conductors 84 and B5,,' is closed to end the tenth impulse. Also, the impulse re- 'sponsive relay '14 of the sender releases and counting relay CH of the chainwill operate as the transfer relays 6B, 59 and 58, armature and front contact of transfer relay 5?, armatures and back contacts of relays 4A and 413, front contacts and armatures of relays 4C and 4D, conductor 1&3, upper frontcontact and armature Relay 16, on operation,

impulse responsive relay 14 will remain released long enough to effect the release of the relay 11. When relay Ti releases, it causes therelease of the counting relays'Clll and CH. -Withthe change-over relay it operated and with the countingrelays all released, the relay 80 is again energized from" the negative pole of battery, winding o f'this relay, frontcontactand armathe change-over relay i6 through the tune of back contactsand armatures of the relays CXto CIl-- inclusive, to the positivepole of battery; When the relay'80 operates, it effects the ener-, gization' of the relay I06 which closes a locking circuit for itself which is effective after relay 80 releases and which is thenin series with the relay I01 and over the conductor 92, in the mann'er previously described. Also, when the relay 106 operates, it interrupts the circuit of the transfer relay 51*nd of the operated register relays causing'these relays to release. 3

At this time, the switchingrelay l3 associated with the cord circuit disconnects'this cord circuit from the sender andcloses break points in this circuit. The operating circuit for the switching relay 13 extends from the negative pole of battery, winding of this relay, outer arma- "tures and front contacts of finder relays 3| and 32, conductor H2, armatureand back contact of relay 4l,:conductor l3, back contacts and arma-' tures of the transfer relays 51, 58, 59 and 60, conductor 81, front 'contact and armature, of the change-over relay 1%, front contact and armature of the relay 12, conductor 42, outer front contact and armature of relay 31, conductor 43, to the v key W. 0. Also, at the time of operation. of the switching relay I 3, it opens the circuit of the cut-off relay I2 ofthe'cord circuit, and also the holding relay 31 0f the sender causing these last named relays to release. It will be recalledthat the locking circuit' of the "relay 12 ofthe sender has been maintained operated at the right-hand front contact and armature of, the. holding relay 31. Thus, when relay 3'! releases, it 'efiects the release of relay 12. All of theoperated relays in sender #1 and in the finder that was used are restored to their released condition. A discharging resistance is placed across the condenser H4. Thus, the #1 sender is in condition to handle another call whenever the common key set is available. It should be pointed out that the operation of the wipe-out key 'W. O. will restore the operated registers of the operated registers of the sender to its normal condition so that it is p'ossibleto start over again if any mistake has been made in the recording of a wanted line designation. v

It will'be noted that relays M and Ma of senders #1 and #2 are inter-locked so that the operation of either one of these relays prevents the operation of the other. The four register control conductors leading from the keys are connected in multiple to contacts of all sender relays, like relay 4 I, in order that these keys can control the register relays in any register as'determined by the particular sender relay which is operated.

The inter-lock prevents the connection of the,

keys to more than one sender at any one time.

7 In the previous description it was pointed out that relay :60 is operated when the first digit is recorded on the thousands relay register and that (A) relay 90 is operated'following the transmission of the first digit and the pause thereafter. Also that (B) relay 59 is operated when the second digit is recorded on the hundreds relay register and that relay 60 is not released until both (A) and (B) have been effected.

Following the transmission of the second digit and the pause thereafter, (C) relay I02 is operated and (D) relay 58 is operated when the third digit is recorded on the tens relay register. Relay 58 is not released until both (C) and (D) have been effected. The same hold off is effected in connection with the third and fourth digits by means of relays ill, 58, I01 and 51. Consequently, impulse transmission is held off, if the operator delays operating the. keys betweendigits, ufitil after the previousdigit and the pause therea er. I

What is claimed is:

1. In an automatic telephone system, a plurality of telephone lines, a plurality of switching devices selectively operated in response to several groups of impulses to'interconnect said lines, an impulse circuit overwhich impulses are transmitted to said switching devices, register means comprising a plurality of selectively operated units for storing thereinthe several digits corresponding to a given selecting condition, impulse generating means including a polarized relay means including a chain of counting relays suc cessively associated with the units of said register and being arranged to count groups of impulses generated by said generating means, the number of impulses in the several groups corresponding to the digits stored in the respective storing units, and means including said chain of relays for governing the transmission of groups of impulses over said impulse circuit, the number of transmitted impulses in each group correspondmg respectively to the number of impulses counted in each group by said relay chain. 5 2. In an automatic telephone system a pluralityof telephone lines, a plurality of switchin devices selectively operated in response to sev eral groups of impulses to interconnect said lines an impulse circuit over which'said impulses are transmitted to said switching devices, register means comprising a'plurality of selectively operachain of counting relays successivelyassociated with the units of said register and being arranged to count'lgrou'ps of directive impulses generated by said generating means, the number of impulses in the several groups corresponding to the digits stored in the respective storing units, means including a given portion of said relay chain for counting a predetermined number of generated impulses to interpose a delay between each of said groups of directive impulses, and means including said chain of relays for governing the transmission of groups of directive impulses over said impulse circuit, the number of transmitted. impulses in each group corresponding respectively to the number of directive impulses counted in each group by'said relay chain.

3. In an automatic telephone system a plurality of telephone lines, a plurality of switching devices selectively operated in response to several groups of impulses to interconnect said lines, an

impulse circuit over which said impulses are transmitted to said switching devices, register means comprising a plurality of selectively operated units for storing therein the several digits corresponding to a Wanted line designation, means including a polarized relay for generating im-, pulses, means including a chain of counting relays successively associated with the units-oi said register and being arranged to count groups of directive impulses generated by said generating means, the number of impulses inthe several groups corresponding to the digits stored in the respective storing units, means including a given portion of said relay chain for countingsa predetermined number of generated impulses to intenpose a delay between each of said groups of directive impulses, and means. includingsaidchain of, relays for governing the transmission-of groups of ,directiveimpulses over said impulse circuit,

the number of transmitted impulsesin each group corresponding respectively to the number of d-irective impulses counted in each group by said relay chain.

. 4 .In an automatic telephone system a plurality of telephone lines a plurality of switching devices selectively operated in response to several groups ofimpulses to interconnect-said lines, an impulse circuit over Whichsaid impulses are transmitted tocontrol said switching devices, a register isender'comprisinga plurality of digit storing units, means for selectively operating said units in succession to store therein digits corresponding to the d'esignati-on of a wanted line, impulse generating means operating continuously, during the storing of digits in said units, means immediately responsive to the completion of the storing of a digiti-n the first unit ofthe sender for transmitting over said impulse circuit a number of impulses corresponding to the digit stored in said first unit, as well as normally continuing the transmission of groups of impulses corresponding to' the digits stored in the remaining units, and means effective as a result of the delayin storing a digit in any of the succeeding units for preventing theffurther transmission over said. im-

pulse circuit of impulses generated by said generating means until such delayed digit is stored.

5. In an automatic telephone system a'plurality of telephone lines, al plural-ity of switching'devices selectively operated in'response to several groups of impulses to interconnect said lines, an impulse circuit over which said impulses. are transmitted to control said switching devices, a sender comprising a register for storing each digit of a wanted line designation, a single set of individual digit keys for repeated operation in eiiecting the registration in said registers of the digits of a wanted line designation, transfer-means for placing each register in succession under the control of said set of keys, impulse generating means operating continuously during the storage of digits in said sender to transmit groups of said generated impulses over said impulses circuit, and means including said transfer means for holding up the transmission of a group of impulses pending the operation of that one of the registers which determines the number of impulses to be included in said last mentioned group.

6. An impulse generator comprising a polarized relay provided with movable contacts and cooperating fixed contacts, certain of which contacts are adapted to generate impulses, said relay having at least a first Winding and a second winding, the first winding when energized in one sense serving to move said movable contacts in one direction and when: energized in the opposite sense serving to move said movable contacts in the opposite direction, circuits effective for alternately energizing said first winding in the mentioned senses, and means including a capacitance and said second winding for controlling the interval of energization of said first winding.

'7. In a register sender, a plurality of register units for registering the number of a called line, a plurality of digit keys, a plurality of digit registering relays for each register unit less in number than the number of said keys, means responsive to the operation of different ones of said keys for operating the digit registering relays of each unit in different combinations, an impulse generating relay, an impulse responsive relay responsive to impulses generated by said impulse generating relay, a plurality of counting relays for counting the impulses generated by said impulse generating relay, means controlled by said impulse generating relay forimpulsing a trunk line circuit to select said called line, test circuits selected by said digit registering relays and said counting relays, and means controlled by the selection of the same test circuit by said digit registering relays and said counting relays for stopping the impulsing of said trunk linecircuit while said impulse generating relay continues to generate impulses.

8 In a register sender, a plurality of register units for registering the number of a called line, aplurality of digit keys, a plurality of digit registering relays for each register unit less in number than the numberzoftsaid keys, means responsive to the operation-of different ones of said keys, for: operating the digit registering relays of each unit indifferent combinations, an impulse generating relay, an impulse responsive relay responsive to impulses generated by said impulse generating relay, a plurality of counting relays for counting the impulses generated by said impulse generating relay, means controlled by said impulse generating. relay for impu-lsing a trunk line circuit to select said called line, test circuits selectesdbysaid digit registering relays and said counting relays, andlmeans controlled by the continued operation of said impulse generating relay after the stopping of the impullsing of said trunk line circuit for causing said impulse responsive relay and saidgc'ounting. relays to measure off the required time interval between digits of .said called line number.

W'INFRED ,T. POWELL. 

